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#include "stddef.h" // for NULL
#include <atomic.h> // for LIBC_LOCK, LIBC_UNLOCK
#include <libc.h> // for libc, libc::(anonymous), libc::LIBC_ENVP_TOUCHED
#include <stdlib.h> // for malloc, realloc, setenv
#include <string.h> // for strlen, size_t, memcpy, strcpy, strchr, strncmp
extern char **environ;
int setenv(const char *var, const char *value, int overwrite)
{
char **env = environ;
size_t var_len = strlen(var);
for (; *env; env++) {
char *eq = strchr(*env, '=');
if (eq && ((size_t)(eq - *env) == var_len) &&
!strncmp(*env, var, var_len)) {
if (overwrite) {
size_t value_len = strlen(value);
char *new_env =
malloc(var_len + 1 + value_len + 1);
if (!new_env)
return -1;
strcpy(new_env, var);
new_env[var_len] = '=';
memcpy(new_env + var_len + 1, value,
value_len + 1);
*env = new_env;
}
return 0;
}
}
size_t env_count = 0;
while (environ[env_count])
env_count++;
char **new_envp = (char **)realloc((void *)environ,
(env_count + 2) * sizeof(char *));
if (!new_envp)
return -1;
size_t value_len = strlen(value);
char *new_var = malloc(var_len + 1 + value_len + 1);
if (!new_var)
return -1;
strcpy(new_var, var);
new_var[var_len] = '=';
memcpy(new_var + var_len + 1, value, value_len + 1);
new_envp[env_count] = new_var;
new_envp[env_count + 1] = NULL;
LIBC_LOCK(libc.lock.environ);
environ = new_envp;
LIBC_UNLOCK(libc.lock.environ);
libc.flags |= LIBC_ENVP_TOUCHED;
return 0;
}
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